Home Forums Hunting & Shooting Gunsmithing JC Higgins Model 50 Mauser

Can I have the scope base holes opened to 8-40 on a Sears JC Higgins Model 50 Mauser? This one has the screws with the wider spacing and closer to the edge of the receiver.

Warne makes bases for this fine rifle.

Rear = M831
Front = M902

Why bother, nothing wrong with the 6-48"s there?

Jim is right.

Talley also makes bases for the M50 JC Higgins with the widely spaced holes.

First couple threads are stripped in the 6-48 there now. Hence the question for opening it up. I have the proper Warne bases.

If only a couple threads are stripped, there should be enough left for a strong hold.

Yes, you can. Simply align your 9/64's endmill so that it "just" cleans up the front edge of the existing hole instead of centering over the hole. That way the new hole won't be materially closer to the front edge of the receiver bridge.

The material in the bridge is pretty thin where the holes are because of the slot for the rib. If one of those holes is stripped it might be worth re-drilling or drilling a new one. My FN only had one hole in the bridge for a long Buehler base so I had another made for use with two-piece bases. The position isn't critical for that.

Those actions were made by FN and many of them are very hard and tough. In addition they are made of different steel than the military 98’s which were made of something similar to 8620 which were case hardened after machining. The material used in that FN can be very difficult to drill and tap. In addition a good heat treated 6-48 screw can hold mounts on a 458 so there isn’t anything to gain.
A lot of upgrades are more for marketing than to rectify a need.

Brownell’s has slightly oversized 6-48 screws which may compensate for the “stripped” threads.

Thanks for the input.

They also require you buy their .146-48 tap and retap the hole(s). It is a viable option but then so is simply converting to the much more readily available 8-40 screw.